The rear wheels of trucks have a generally cylindrical section around which a tire is mounted and the wheel is retained to the axle hub by lug nuts extending from a flange mounted on the axle hub and through holes in the web of the wheel. The distal end of the axle hub extends through the center of the wheel and often has a removable oil hub into which lubricating material may be inserted.
For large trucks, the portion of the rear axle hub which extends through the central opening of a wheel is typically 8xc2xd inches in diameter. Many manufacturers market a decorative covering or xe2x80x9chigh hatxe2x80x9d for enclosing the distal end of a truck axle hub and these decorative covers have an inner diameter which is a little larger than the 8xc2xd inch diameter of the axle. There are many methods for retaining a covering over a truck axle hub and one method, described in my prior U.S. Pat. No. 5,366,279, requires a foam sleeve which is fitted around the end of the truck axle hub.
There are circumstances under which a decorative cover being retained over the axle hub of a wheel must be repeatedly removed. For example, the state of California requires that the webs of truck wheels be frequently checked for cracks near the holes for the lug nuts. I have found that after several removals and reinstallations of a wheel cover retained using the apparatus of my U.S. Pat. No. 5,366,279, the foam sleeve becomes damaged replacement is required. There is, therefore, a need for a more durable or reusable apparatus for retaining a cover over the axle hub.
Smaller trucks and some trailers have axle hubs that are 6xc2xc inches in diameter, and it is the practice to cover 6xc2xc inch axles with the same size cover used to cover the 8xc2xd inch axle hubs. There is considerably more space between the outer surface of a 6xc2xc inch axle hub and the inner surface of the standard size wheel than is the case for an 8xc2xd inch axle hub, and a correspondingly thicker foam sleeve is required where the method of my U.S. Pat. No. 5,366,279 is to be employed to retain a cover to a 6xc2xc inch diameter axle hub. There is, therefor, also a need for a better method for retaining a decorative axle hub cover over the axle hubs having either 6xc2xc inches or 8xc2xd inch diameters.
Briefly, the present invention is embodied in an attachment for retaining a generally tubular cover with an open end and a closed end over the distal end of a generally cylindrical axle hub. To retain the cover an annular strap is provided which is tightened around the circumference of the axle hub so as to be retained in place. The strap has a plurality of spring loaded radially extending prongs spaced around the circumference thereof. The prongs have arms which extend radially outward of the outer surface of the strap and the ends thereof define a circle having a diameter which is a little greater than the inner diameter of the cylindrical cover.
Although some truck axle hubs are cylindrical, most have a plurality of equally spaced longitudinal ribs between which are grooves. Most 8xc2xd inch truck axle hubs have eight ribs, and many 6xc2xc inch truck axle hubs have twelve ribs. To provide support to the prongs, the prongs are spaced apart by a distance equal to the arc length between two ribs, or equal to a multiple of the arc length between two ribs. When the strap is fastened around the axle hub of a wheel, all of the prongs are positioned to be over ribs such that a rib will radially support the inner surface of each prong. The tubular cover is then fitted over the radially extending spring prongs and is retained in place by the radially outwardly directed forces applied by the prongs against the inner surface of the cylindrical cover.